In various types of electronic instruments, such as oscilloscopes and spectrum analyzers, it is desirable that high frequency signals be connected selectively between conductors without substantial reflection or attenuation of the signal. Several kinds of mechanically-actuated switches have been proposed for this purpose. For example, U.S. Pat. No. 3,719,788 issued Mar. 6, 1973 discloses a cam-actuated switch comprising a metal contact member carried by a cam follower that is mounted in cantilever fashion to a circuit board. A rotatable cam engages the cam follower, and during the dwell of the cam the metal contact member is pressed into contact with two conductor runs of the circuit board and establishes electrical connection between those conductor runs. In order for the connection provided by this type of switch to have consistent electrical characteristics, it is necessary that the contact force between the metal contact member and the conductor runs be the same each time the switch is actuated by engagement of the cam follower by the cam dwell. In order to provide consistent contact force, precision bearings are required for the cam shaft. If the same cam shaft is used to actuate several switches the force is consistent from switch to switch only if the cam itself is a precision part and the surface of the circuit board is flat within quite small tolerances and is parallel to the axis of rotation of the cam. Moreover, because the cam follower is cantilever-mounted, it is difficult to achieve and maintain proper alignment of the metal contact member and the conductor runs.
Another type of switch having good high-frequency characteristics is shown in U.S. Pat. No. 4,150,420 issued Apr. 17, 1979. The switch shown in that patent is subject to much the same disadvantages as the switch of U.S. Pat. No. 3,719,788.